有趣的运算。。。
<?php $d = 10; function f($d){ return ++$d; } //$d = f($d++); //$d = f($d); // f($d++); f($d); echo "d is:" . $d; ?>
解析:
$d = f($d++); //1-->$d = f(10);f(10)-->return 11; //2-->$d = 11;
$d = f($d); //1-->$d = f(10);f(10)-->return 11; //2-->$d = 11;
f($d++); //1-->f($d++);f(10);不管它------ -->$d++;-->11; //2-->$d = 11;
f($d); //$d没变，自然为10
原文：http://www.cnblogs.com/haidong/p/4371600.html